1 June 1944
Dear Doctor Heidelberger:
The Air Surgeon is planning at the suggestion and with the advice of Doctor MacLeod to conduct a study at the Amy Air Base at Sioux Falls, South Dakota during the coming year in the prevention of pneumococcal pneumonia with the specific capsular carbohydrates.  Miss Pauli whom you may know is setting up plans in regard to personnel and equipment.  She will be responsible for the training of the personnel involved and for the bacteriological portion of the study.  I have asked her to discuss with you other phases of the purposed study and to get your advice and recommendations concerning them.
Doctor MacLeod has mentioned the possibility of your doing an agglutination study of the serological response produced by vaccination as mentioned above.  I hope that it will be possible to work this out so that it can be done by you or under your supervision. We have of course adequate funds for the development of projects of this kind.
Very sincerely yours,
Arie C. van Ravenswaay
Major, Medical Corps
Assistant, Medical Services Division
Office of the Air Surgeon